steph, don't get discouraged. you can only do what you can do. if a stroll is all you can do, then at least a stroll is better than sitting on the couch, eating. also, i'm not an exerciser, but i'm pretty sure that reps are more important than weight when it comes to trying to tone your arms.
another thing, chicago was in between meeting your goal weight and now, and i have to say any weight gained from that was totally worth it. SO MUCH FUN! you are probably just still dehydrated and retaining water from that, lol. don't get down on yourself!